When an IP (Internet Protocol) telephone is exchanged due to a failure in an IP telephone exchange system, there is a case where the same extension number (additionally including one touch button settings, settings of a telephone book to use and the like) as that of the IP telephone before the exchange needs to be used for an operation. In this case, it is necessary to manually change a management table of the extension number and MAC addresses (Media Access Control addresses) of IP telephones managed inside an exchange.
Patent Literature 1 discloses a technique which relates to the present invention, and which, when a failed thin client terminal is changed to a maintenance terminal, an administrator user makes an instruction via a terminal replacement instruction screen transmitted from a management server to a management terminal to take over settings of a network device such as an IP address and a host name of the failed thin client terminal to a maintenance terminal.